Hello!
First time poster, so please forgive me if this post is in the incorrect location.
I recently received back a series of prototype PCB boards for IC testing. All the usual assembled components on the board; Resistors, Caps, Level shifters, PGA socket, etc etc. However additionally room was included on the boards to test specific IPDIA capacitors on the board, which the assembly was not able to include as they must be attached to the board with epoxy and wire bonded to 4 pads on the board; basically like a simple Chip-on-board. The PCBs were made with pads places for this Al/Au wire bonding and an ENIPEG surface finish was chosen to ensure the bonding process would be possible.
The problem is when the board was sent from manufacturing to assembly and the IPDIA caps were set as do-not-assemble parts, they still applied a small layer of solder to the exposed ENIPEG bonding pads. Now the wire-bonding team are telling me they cannot bond to this surface.
Can the pads be easily scrubbed?
The Bonding Expert suggested I get some small gold plated squares (60mil x 60mil or so approx) and have them soldered to the bonding pads to provide a suitable surface however I am at a loss as to where to source such metal parts, considering his direct reference was for parts from "SPM", a company 7+ years gone.
Any other ideas? The primary limitation is time (not money, within reason) as we are on a rushed timeline to test the boards.
Thankyou